The Science of Scrumptious Food

Los Angeles magazine called Amy Rowat’s lecture series at UCLA “a mind-blowingly awesome event.” Not a description you’d normally expect for a university class. Then again, who knew you could learn serious science by working with Jell-O, cream cheese, apple pie and bake-offs?

Photo by: Gregg Segal

Amy Rowat, assistant professor in the UCLA Department of Integrative Biology & Physiology, pioneered the use of examples from food and cooking as vehicles for teaching sophisticated physics concepts to a general audience. She is the co-developer of the first annual Harvard Science & Cooking course and is founder and director of Science & Food, an organization based at UCLA that promotes knowledge of science through food and food through science.

Why teach science through food?

When we eat, we don’t stop to think that we’re consuming biological material — plant or animal — that has been manipulated through molecular alteration (acted upon by other ingredients and cooked). But preparing food can be a powerful way to understand the effect of mechanical and chemical environments on cellular behavior.

Rowat first realized this as a postdoctoral fellow at Harvard, in the School of Engineering & Applied Sciences. Celebrated Spanish chef Ferran Adriá delivered a lecture that inspired Rowat and a colleague to offer a course focused on haute cuisine. Students learned about “spherification” — the process of turning a liquid into a gel, used by chefs to create such wonders as mozzarella balls and “fake” caviar. Well-known chefs came in as guest speakers. The class was a huge success and is now offered annually.

Amy Rowat: Scientist & Foodie

An assistant professor at UCLA's Department of Integrative Biology and Physiology, Amy Rowat believes food is a great medium to showcase science to a broad audience.

So when Rowat came to UCLA in 2011, she wanted to do something similar. The UCLA course covers the role of gels in physiology and in food. For example, students learn why different cuts of meat have different textures and must be cooked differently. Rowat says it’s because they have different amounts of collagen, the substance that provides a structure for tissues.

She also explains how cooking alters the interactions between molecules and how factors such as temperature, acidity and salt content affect the flavor and safety of food. She and the students address such questions as what makes lettuce crisp? How do you create and stabilize air pockets in a soufflé? Why is honey viscous while sugar water is not? In short, they learn science while discovering what’s behind the flavor and texture of some of their favorite dishes.

What’s Cookin’ in the Lab

Rowat is also concerned with texture in the lab — texture of cells, which she says can indicate health or disease. For instance, softer cells can deform faster than stiffer ones, and cancer cells are generally two to four times softer than normal ones. Just as “networks of protein molecules are essential for the texture of bread and Jell-O,” she says, they’re also “critical to the texture of individual cells, such as ovarian cancer cells.”

Amy Rowat's TEDx Lecture

Amy Rowat talks about the science behind the food we eat, at a UCLA-organized TEDx event.

The Canadian biophysicist is particularly interested in questions such as: What determines the size and shape of a cell’s nucleus? How rigid or squishy are nuclei in different cell and tissue types? When the nucleus changes shape, what is the impact on the physiological functions of the cell and other cell components? She addresses these by probing cells, tissues and organisms, merging molecular biology methods with physical science techniques.

Food for Thought

Lessons learned in class make their way to the lab. After seeing how pressure inside cells affects the texture of foods, such as the crispness of lettuce or apples, Rowat was prompted to study how the nucleus of plant cells withstands a large amount of pressure.

And after students extracted flavor molecules from herbs by placing them in whipped-cream canisters and applying and releasing pressure (to infuse the flavor of herbs into alcohol — creating, for example, sage-flavored martinis), a researcher in the lab found that the canister also could be used to isolate nuclei from plant cells.

Easy as Apple Pie

As a game to get students to practice the scientific method, Rowat offers a bake-off. Students make apple pies, experimenting with the physical characteristics of their creations. They assess such properties as the “structural stability” of their crusts, measuring pastry density by using kitchen scales. They try out different fat sources in the crust.

They learn that adding alcohol or vinegar to crust can impede gluten formation, helping to promote flakiness. Using pH paper, they gauge the acidity of their apples. When they’re finished, the pies are judged by a panel of chefs, food critics and UCLA scientists. And voila! The scientific method never tasted so good.

Culinary Artists

The popularity of Rowat’s course prompted her to offer related public lectures conducted with A-list chefs. (And faculty in other disciplines say they, too, want to use food to teach such topics as sustainability and sensory perception.) The events, which sell out quickly, are meant to introduce the general public to food science.

“Our goals are to get people to think more critically about the food they eat and where it comes from and to begin thinking about the role of science in everyday life,” Rowat says.

Chefs who have appeared include Alice Waters, founder and owner of Chez Panisse in Berkeley; Zoe Nathan, award-winning chef of several Los Angeles eateries; Christina Tosi, winner of the James Beard Rising Star Chef Award and head of New York’s Momofuku Milk Bar; and Bill Yosses, executive pastry chef at the White House. Their lecture topics have ranged from “Why Do Carrots Taste Sweeter in the Winter?” to “The Molecules of Food and the Exploration of Deliciousness.”